1. Technical Field
The present invention relates to a heat exchanger having a plurality of fine flow channels, a method of manufacturing the heat exchanger, and so on.
2. Related Art
In recent years, reduction in size, increase in intensity, elongation in lifetime, reduction in cost, and so on have been attempted for a projector. For example, as regards reduction in size, the size of a liquid crystal panel (light modulation element) is on the order from 1.3 inches to 0.5 inches between opposed corners, and is reduced by ⅙ or a little more in area ratio.
Reduction in size is achieved by using a Light Emitting Diode (LED) or a Laser Diode (LD) which are solid light sources as a light source for the projector. The LED light source is compact including a power source, and has merits preferable as the light source for the projector, such that rapid ON-OFF is possible, the range of color reproduction is wide, a lifetime is long, and so on. Since harmful substances such as mercury is not included, it is preferable in terms of environmental protection.
However, since heat generation from the LED light source is increased and hence light emitting efficiency is lowered in association with increase in intensity of the LED light source or the like, it is necessary to take a countermeasure for heat generation. In a compulsory air-cooling system with a fan, which is generally employed, there are problems such that the cooling efficiency is not sufficient, or the fan makes a noise.
Therefore, there is proposed a method of compulsorily cooling the LED light source or the like using the heat exchanger having a plurality of flow channels for allowing passage of liquid. As such a heat exchanger, a method of forming a plurality of flow channels by laminating and brazing a plurality of thin plates as shown in JP-A-2005-166855.
However, in the technology shown above, there is a risk that a brazing filler metal used for joining the thin plates flows into the flow channels may clog the flow channels. Since brazing filler metal is interposed between the thin plates, there arises a problem such that coefficient of thermal conductivity in the direction of lamination of the thin plates is significantly lowered. In addition, since metal different from the thin plates is interposed occurrence of electrolytic corrosion becomes an issue.